UNDERGROUND GAS STORAGE DEVICE FOR COMPRESSED AIR ENERGY STORAGE AND CONSTRUCTION PROCEDURE THEREOF

Abstract

Disclosed in the present invention are an underground gas storage device for compressed air energy storage and a construction method therefor. The underground gas storage device for compressed air energy storage comprises an underground gas storage cavern, the underground gas storage cavern being formed of a plurality of underground gas storage cavern sections, wherein a connecting tunnel is provided between two non-adjacent underground gas storage cavern sections, a vertical shaft is provided at the top end of the connecting tunnel, and a sealing plug is provided in the intersection between the vertical shaft and the connecting tunnel; a gas intake pipeline and a gas output pipeline are provided in the vertical shaft, and a sump is provided on an outer bottom wall of the connecting tunnel; a first drainage ditch is provided around the top face edge of the sealing plug in the vertical shaft, and the first drainage ditch is in communication with the sump; and a drainage blind pipe assembly is provided on the periphery of the underground gas storage cavern sections, and the drainage blind pipe assembly is in communication with the sump via a second drainage ditch arranged at the outer bottom wall of the connecting tunnel. The present invention can achieve one-time excavation forming, without transformation and with relatively low construction difficulty, and can effectively reduce the influence of underground water on the underground gas storage cavern during a construction period, operation period and maintenance period.

Description

A compressed air energy storage underground gas storage device and construction method thereof Technical Field

[0001] The present invention belongs to the technical field of underground structural engineering, and specifically relates to a compressed air energy storage underground gas storage device and a construction method thereof. Background Art

[0002] Compressed air energy storage power stations are mainly used to cooperate with wind power generation, tidal power generation and hydropower generation. They convert excess electricity in the power grid during periods of low power load into the potential energy of compressed air and store it in the gas storage device. During peak power consumption periods, the compressed air is released to generate electricity, effectively alleviating the intermittent and random fluctuations of renewable energy power generation and improving the absorption level of renewable energy power generation. Compressed air energy storage is an electric energy storage technology that can achieve large-capacity and long-term energy storage.

[0003] In addition, compared with pumped storage, the gas storage device of compressed air energy storage has the advantages of short construction period, less geographical restrictions on site selection, and flexible layout; compared with electrochemical energy storage, compressed air energy storage has the advantages of large capacity, long discharge duration, high safety, low environmental pollution, and strong adaptability to high and low temperatures, and the gas storage device of compressed air energy storage has a long life.

[0004] However, existing compressed air energy storage projects have the following problems: 1) For compressed air energy storage projects where gas storage devices are installed underground, underground energy storage devices can be divided into mined or specially excavated rock salt cavities, mined underground gas storage reservoirs or underground oil storage reservoirs, and artificially excavated underground caverns according to different geographical structures. Except for artificially excavated underground caverns, the remaining underground energy storage devices can be directly used to store compressed gas after exploration, but the cost is high and their promotion and use are limited by geological conditions. In addition, the stress conditions of special-shaped underground energy storage devices are poor and stress-deformation analysis is more difficult. In addition, the transformation of existing underground caverns into gas storage caverns often has complex construction conditions and high technical difficulty. 2) For compressed air energy storage projects where gas storage devices are installed on the ground, the production of large-span and long-distance above-ground pipeline steel is difficult, costly, and has high safety risks. In addition, since the internal pressure of the gas storage space often exceeds 10MPa, according to the pressure vessel design specifications, the thickness of the sealing steel exceeds 5cm, which is difficult to manufacture and the cost is very high.

[0005] Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the present invention provides a compressed air energy storage underground gas storage device and a construction method thereof, which can be excavated and formed in one time without the need for modification, has relatively low construction difficulty, and can effectively reduce the impact of groundwater on the underground gas storage cavern during the construction period, operation period and maintenance period.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A compressed air energy storage underground gas storage device comprises an underground gas storage cavern in underground surrounding rock, wherein the underground gas storage cavern is formed by multiple underground gas storage cavern segments spliced ​​end to end in sequence, wherein a connecting tunnel is provided between two non-adjacent underground gas storage cavern segments, a vertical shaft connected to the ground is provided at the top of the connecting tunnel, a sealing plug is provided at the intersection of the vertical shaft and the connecting tunnel, an air inlet pipe and an air outlet pipe are provided in the vertical shaft, the lower ends of the air inlet pipe and the air outlet pipe both pass through the sealing plug and are connected to the connecting tunnel, a water collection well is provided at the outer bottom wall of the connecting tunnel, a first drainage ditch is provided around the top edge of the sealing plug in the vertical shaft, the first drainage ditch is connected to the water collection well through a first drainage pipe, a drainage blind pipe assembly is provided on the outer periphery of the underground gas storage cavern segments, and the drainage blind pipe assembly is connected to the water collection well through a second drainage ditch provided at the outer bottom wall of the connecting tunnel.

[0009] Furthermore, the underground gas storage cavern segments are cylindrical in shape, adjacent underground gas storage cavern segments are integrally connected and the connection is in an arc shape, and the connecting tunnels are integrally connected to the corresponding underground gas storage cavern segments.

[0010] Furthermore, the air intake pipe is a three-way pipe, including a vertically arranged first air intake pipe segment and two horizontally arranged second air intake pipe segments, the upper part of the first air intake pipe segment is in the vertical shaft and the lower part is in the sealing plug below the vertical shaft, one section of the second air intake pipe segment is in the sealing plug on one side below the vertical shaft, and the other section of the second air intake pipe segment is in the sealing plug on the other side below the vertical shaft, one end of the second air intake pipe segment is connected to the lower end of the first air intake pipe segment, and the other end passes through the sealing plug and is connected to the connecting tunnel.

[0011] Furthermore, the structure of the air outlet pipe is the same as that of the air inlet pipe. The air outlet pipe includes a first air outlet pipe segment arranged vertically and two second air outlet pipe segments arranged horizontally. The air outlet pipe is used as an inspection pipe. An inspection port is provided at the first air outlet pipe segment near the top surface of the sealing plug, and a sealing blind plate is provided at the inspection port.

[0012] Furthermore, a second drainage pipe is provided in the vertical shaft, the lower end of the second drainage pipe extends into the water collection well and the upper end of the second drainage pipe extends to the ground and is connected to a water pump.

[0013] Furthermore, the water collection well is located at the outer bottom wall of the connecting tunnel below the vertical shaft, the first drainage pipe is passed through the sealing plug and the lower end extends into the water collection well, the second drainage ditch is arranged along the extension direction of the connecting tunnel and on the entire outer bottom wall of the connecting tunnel, and the lower part of the second drainage pipe is passed through the sealing plug.

[0014] Furthermore, the drainage blind pipe assembly includes multiple annular drainage blind pipes and multiple longitudinal drainage blind pipes. The annular drainage blind pipes are arranged in an annular manner around the outer surface of the underground gas storage cavern segment. The axis of the longitudinal drainage blind pipe coincides with the axis of the underground gas storage cavern segment and is arranged at a corresponding position on the outer surface of the underground gas storage cavern segment. The longitudinal drainage blind pipe at the bottom of the outer surface of the underground gas storage cavern segment is called a bottom longitudinal drainage blind pipe. Each of the annular drainage blind pipes is connected to each longitudinal drainage blind pipe, and the bottom longitudinal drainage blind pipe in the underground gas storage cavern segment connected to the connecting roadway is connected to the second drainage ditch.

[0015] Furthermore, the horizontal heights of both ends of the bottom surface of the underground gas storage cavern segment connected to the connecting tunnel are higher than the horizontal height of the bottom surface at the position connected to the connecting tunnel.

[0016] Furthermore, the underground gas storage cavern segment comprises a concrete spraying layer, a reinforced concrete lining layer and a sealing layer from the outside to the inside, and the sealing layer is formed by welding a plurality of steel plates end to end in sequence.

[0017] A construction method for a compressed air energy storage underground gas storage device comprises the following steps:

[0018] S1. First, excavate the vertical shaft. After the vertical shaft is penetrated, excavate connecting tunnels in two working faces with the vertical shaft as the center. When excavating the connecting tunnel, excavate a water collection well at the outer bottom wall of the connecting tunnel, and arrange a second drainage ditch at the outer bottom wall of the connecting tunnel. After the connecting tunnel is penetrated, excavate an underground gas storage cavern segment connected to the connecting tunnel through the connecting tunnel. Then, excavate other underground gas storage cavern segments through the excavated underground gas storage cavern segments. When excavating the underground gas storage cavern segments, arrange drainage blind pipe assemblies on the outer periphery of the underground gas storage cavern segments, and connect the drainage blind pipe assemblies to the second drainage ditch.

[0019] S2. After all the underground gas storage cavern segments are excavated, a sealing plug is arranged at the intersection of the vertical shaft and the connecting tunnel, and an air inlet pipe and an air outlet pipe are arranged in the vertical shaft, and the lower ends of the air inlet pipe and the air outlet pipe are passed through the sealing plug and connected to the connecting tunnel, and then the first drainage ditch around the top edge of the sealing plug in the vertical shaft is connected to the water collection well through the first drainage pipe.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The compressed air energy storage underground gas storage device of the present invention can fully utilize the strength of the surrounding rock to resist internal pressure because the underground gas storage cavern is located in the underground surrounding rock, thereby reducing the investment cost of sealing materials and support engineering in the underground gas storage cavern; since a water collection well is provided at the outer bottom wall of the connecting tunnel, a first drainage ditch is provided around the edge of the top surface of the sealing plug in the vertical shaft, and the first drainage ditch is connected to the water collection well through the first drainage pipe, which can effectively drain the accumulated water in the vertical shaft and ensure the durability of the facilities in the vertical shaft; since a drainage blind pipe assembly is provided on the outer periphery of the underground gas storage cavern segment, the drainage blind pipe assembly is connected to the water collection well through the second drainage ditch provided at the outer bottom wall of the connecting tunnel, which can effectively reduce the underground gas storage cavern from being affected during the construction period, operation period and maintenance period. The impact of groundwater; in addition, before excavating the underground gas storage cavern, a vertical shaft is excavated first. After the vertical shaft is penetrated, connecting tunnels are excavated in two working faces with the vertical shaft as the center. After the connecting tunnel is penetrated, the underground gas storage cavern segments connected to the connecting tunnel are excavated through the connecting tunnel, and then other underground gas storage cavern segments are excavated through the excavated underground gas storage cavern segments. In this way, the vertical shaft is used as a construction channel for excavating the underground gas storage cavern, and there is no need to build an additional construction channel. While speeding up the construction progress, it can save temporary project investment. Moreover, compared with using the existing underground caverns as gas storage caverns, the compressed air energy storage underground gas storage device of the present invention can be excavated and formed at one time, without the need for modification, and the construction difficulty is relatively small, which is conducive to construction risk control.

[0022] In the present invention, the underground gas storage cavern segments are cylindrical in shape, adjacent underground gas storage cavern segments are integrally connected and the connection is in the shape of a circular arc, and the connecting tunnels are integrally connected to the corresponding underground gas storage cavern segments and the connection is in the shape of a circular arc; in this way, the underground gas storage cavern segments have a circular cross-section and good stress conditions. In addition, since the underground gas storage caverns are formed by splicing multiple cylindrical underground gas storage cavern segments end to end in sequence, the line layout direction of the underground gas storage caverns is flexible, the position change is flexible, the airflow connectivity is good, and the dependence on geological conditions can be reduced to a certain extent.

[0023] In the present invention, since the air intake pipe is a three-way pipe, including a first air intake pipe segment arranged vertically and two second air intake pipe segments arranged horizontally, the upper part of the first air intake pipe segment is in the vertical shaft and the lower part is in the sealing plug below the vertical shaft, one section of the second air intake pipe segment is in the sealing plug on one side below the vertical shaft, and the other section of the second air intake pipe segment is in the sealing plug on the other side below the vertical shaft, one end of the second air intake pipe segment is connected to the lower end of the first air intake pipe segment, and the other end passes through the sealing plug and is connected to the connecting tunnel; in this way, the compressed air entering the first air intake pipe segment can enter the connecting tunnels on both sides of the vertical shaft through the two sections of the second air intake pipe segments, and can then quickly enter the entire underground gas storage cavern.

[0024] In the present invention, since the structure of the air outlet pipe is the same as that of the air inlet pipe, the air outlet pipe includes a first air outlet pipe segment arranged vertically and two second air outlet pipe segments arranged horizontally. In this way, the compressed air in the underground gas storage cavern can quickly enter the first air outlet pipe segment through the two second air outlet pipe segments after entering the connecting tunnels on both sides of the vertical shaft; since the air outlet pipe is used as a maintenance pipe, an inspection port is provided at the first air outlet pipe segment near the top surface of the sealing plug, and a sealing blind plate is provided at the inspection port. In this way, when the underground gas storage cavern needs to be inspected, the staff enters the vertical shaft and opens the sealing blind plate, and passes through the first air outlet pipe segment and the second air outlet pipe segment in turn to enter the connecting tunnel, and then enters the underground gas storage cavern through the connecting tunnel to carry out maintenance work. In addition, since the air outlet pipe and the inspection pipe share a pipe, this can indirectly reduce the construction workload.

[0025] In the present invention, the drainage blind pipe assembly includes a plurality of annular drainage blind pipes and a plurality of longitudinal drainage blind pipes. The annular drainage blind pipes are arranged annularly around the outer surface of the underground gas storage cavern segment. The axis of the longitudinal drainage blind pipe coincides with the axis of the underground gas storage cavern segment and is arranged at a corresponding position on the outer surface of the underground gas storage cavern segment. The longitudinal drainage blind pipe located at the bottom of the outer surface of the underground gas storage cavern segment is called a bottom longitudinal drainage blind pipe. Each annular drainage blind pipe is connected to each longitudinal drainage blind pipe. The bottom longitudinal drainage blind pipe in the underground gas storage cavern segment connected to the connecting roadway is connected to the second drainage ditch. In this way, the groundwater at the underground gas storage cavern segment can enter the bottom longitudinal drainage blind pipe in sequence through the annular drainage blind pipe and the remaining longitudinal drainage blind pipes except the bottom longitudinal drainage blind pipe, and the groundwater in the bottom longitudinal drainage blind pipe in the underground gas storage cavern segment that is not connected to the connecting tunnel can enter the bottom longitudinal drainage blind pipe in the underground gas storage cavern segment that is connected to the connecting tunnel, and the groundwater in the bottom longitudinal drainage blind pipe in the underground gas storage cavern segment that is connected to the connecting tunnel can enter the water collection well through the second drainage ditch, so the groundwater at the underground gas storage cavern segment can be quickly discharged into the water collection well. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic diagram of the three-dimensional structure of the underground gas storage device for compressed air energy storage in the present invention;

[0027] FIG2 is a schematic diagram of a top view of a cross-sectional structure of a compressed air energy storage underground gas storage device according to the present invention;

[0028] FIG3 is a partial enlarged schematic diagram of point B in FIG2 ;

[0029] FIG4 is a schematic cross-sectional view of the compressed air energy storage underground gas storage device according to the present invention along the AA direction in FIG2 ;

[0030] FIG5 is a partial enlarged schematic diagram of FIG4;

[0031] FIG6 is a schematic diagram of an enlarged partial cross-section of one of the underground gas storage cavern segments.

[0032] Explanation of the reference numerals in the figure: 1. underground gas storage cavern, 101. underground gas storage cavern segment, 1011. concrete spraying layer, 1012. reinforced concrete lining layer, 1013. sealing layer, 2. connecting tunnel, 3. vertical shaft, 4. sealing plug, 5. air inlet pipe, 6. air outlet pipe, 601. first air outlet pipe segment, 602. second air outlet pipe segment, 7. water collection well, 8. first drainage ditch, 9. first drainage pipe, 10. second drainage ditch, 11. sealing blind plate, 12. second drainage pipe, 13. circumferential drainage blind pipe, 14. longitudinal drainage blind pipe, 15. bottom longitudinal drainage blind pipe, 16. staggered tunnel. DETAILED DESCRIPTION

[0033] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0037] As shown in Figures 1-5, a compressed air energy storage underground gas storage device includes a tunnel-type underground gas storage cavern 1 in the underground surrounding rock. The underground gas storage cavern 1 is formed by splicing multiple underground gas storage cavern segments 101 end to end in sequence, wherein a connecting tunnel 2 is provided between two non-adjacent underground gas storage cavern segments 101, and a vertical shaft 3 connected to the ground is provided at the top of the connecting tunnel 2. A sealing plug 4 is provided at the intersection of the vertical shaft 3 and the connecting tunnel 2. An air inlet pipe 5 and an air outlet pipe 6 are provided in the vertical shaft 3. The lower ends of the air inlet pipe 5 and the air outlet pipe 6 pass through the sealing plug 4 and are connected to the connecting tunnel 2. A water collection well 7 is provided on the outer bottom wall of the connecting tunnel 2 below the vertical shaft 3. A circular first drainage ditch 8 is provided around the edge of the top surface of the sealing plug 4 in the vertical shaft 3. The first drainage ditch 8 is connected to the water collection well 7 through the first drainage pipe 9, wherein the first drainage pipe 9 is passed through the sealing plug 4 and the lower end extends into the water collection well 7, and a drainage blind pipe assembly is provided on the outer periphery of the underground gas storage cavern segment 101. The drainage blind pipe assembly is connected to the water collection well 7 through a second drainage ditch 10 arranged at the outer bottom wall of the connecting tunnel 2, wherein the second drainage ditch 10 is arranged along the extension direction of the connecting tunnel 2 and on the entire outer bottom wall of the connecting tunnel 2.

[0038] Since the underground gas storage cavern 1 is located in the underground surrounding rock, it can make full use of the surrounding rock strength to resist internal pressure, thereby reducing the investment cost of sealing materials and support projects in the underground gas storage cavern 1; since a water collection well 7 is provided at the outer bottom wall of the connecting tunnel 2, a first drainage ditch 8 is provided around the top edge of the sealing plug 4 in the vertical shaft 3, and the first drainage ditch 8 is connected to the water collection well 7 through a first drainage pipe 9, which can effectively drain the accumulated water in the vertical shaft 3 and ensure the durability of the facilities in the vertical shaft 3; since a drainage blind pipe assembly is provided on the outer periphery of the underground gas storage cavern segment 101, the drainage blind pipe assembly is connected to the water collection well 7 through a second drainage ditch 10 provided at the outer bottom wall of the connecting tunnel 2, which can effectively reduce the impact of groundwater on the underground gas storage cavern 1 during the construction period, operation period and maintenance period; in addition Before excavating the underground gas storage cavern 1, a vertical shaft 3 is excavated first. After the vertical shaft 3 is penetrated, a connecting tunnel 2 is excavated in two working faces with the vertical shaft 3 as the center. After the connecting tunnel 2 is penetrated, an underground gas storage cavern segment 101 connected to the connecting tunnel 2 is excavated through the connecting tunnel 2, and then other underground gas storage cavern segments 101 are excavated through the excavated underground gas storage cavern segments 101. In this way, the vertical shaft 3 is used as a construction channel for excavating the underground gas storage cavern 1, and there is no need to build an additional construction channel. While speeding up the construction progress, it can save temporary project investment. Moreover, compared with using the existing underground cavern as a gas storage cavern, the compressed air energy storage underground gas storage device of the present invention can be excavated and formed at one time, without the need for modification, and the construction difficulty is relatively small, which is conducive to construction risk control.

[0039] In one embodiment, as shown in FIG1 , the underground gas storage cavern segments 101 are cylindrical in shape, and adjacent underground gas storage cavern segments 101 are integrally connected and the connection is in the shape of a circular arc. The connecting tunnel 2 is integrally connected to the corresponding underground gas storage cavern segments 101. Thus, the underground gas storage cavern segments 101 have a circular cross-section, which provides good stress-bearing conditions. In addition, since the underground gas storage cavern 1 is formed by splicing multiple cylindrical underground gas storage cavern segments 101 end to end, the layout direction of the underground gas storage cavern 1 is flexible, the position can be changed flexibly, the airflow connectivity is good, and the dependence on geological conditions can be reduced to a certain extent. Preferably, the gas storage circuit of the underground gas storage cavern 1 is rectangular in shape, the underground gas storage cavern segments 101 are four sections, and the connecting tunnel 2 connects the underground gas storage cavern segments 101 that serve as the two long sides of the underground gas storage cavern 1 and is arranged in the middle of the underground gas storage cavern 1. Preferably, the vertical shaft 3 is located at the middle of the top of the connecting tunnel 2, and is used as the main passage during the construction period of the underground gas storage cavern 1 and the maintenance passage during the maintenance period.

[0040] In one embodiment, the air intake duct 5 is a three-way pipe, comprising a first air intake duct segment arranged vertically and two second air intake duct segments arranged horizontally. The upper portion of the first air intake duct segment is located in the vertical shaft 3, and the lower portion is located in the sealing plug 4 below the vertical shaft 3. One of the second air intake duct segments is located in the sealing plug 4 on one side below the vertical shaft 3, and the other second air intake duct segment is located in the sealing plug 4 on the other side below the vertical shaft 3. One end of the second air intake duct segment is connected to the lower end of the first air intake duct segment, and the other end passes through the sealing plug 4 and is connected to the connecting tunnel 2. In this way, the compressed air entering the first air intake duct segment can enter the connecting tunnels 2 on both sides of the vertical shaft 3 through the two second air intake duct segments, and then can quickly enter the entire underground gas storage cavern 1. The sealing plug 4 plays a sealing role, preventing the compressed air in the underground gas storage cavern 1 from directly entering the vertical shaft 3 through the connecting tunnel 2.

[0041] In one embodiment, the structure of the air outlet pipe 6 is the same as that of the air inlet pipe 5. As shown in Figures 4-5, the air outlet pipe 6 includes a first air outlet pipe segment 601 arranged vertically and two second air outlet pipe segments 602 arranged horizontally. In this way, the compressed air in the underground gas storage cavern 1 can quickly enter the first air outlet pipe segment 601 through the two second air outlet pipe segments 602 after entering the connecting tunnels 2 on both sides of the vertical shaft 3; the air outlet pipe 6 is used as a maintenance pipe, and an inspection port is provided at the first air outlet pipe segment 601 near the top surface of the sealing plug 4, and a sealing blind plate 11 is provided at the inspection port. In this way, when the underground gas storage cavern 1 needs to be inspected, the staff enters the vertical shaft 3 and opens the sealing blind plate 11, and passes through the first air outlet pipe segment 601 and the second air outlet pipe segment 602 in turn to enter the connecting tunnel 2, and then enters the underground gas storage cavern 1 through the connecting tunnel 2 to perform maintenance work. In addition, since the air outlet pipe 6 and the inspection pipe share a pipe, this can indirectly reduce the construction workload. Among them, the first air outlet pipe segment 601 is a variable diameter pipe, the diameter of the first air outlet pipe segment 601 above the inspection port is smaller than the diameter of the first air outlet pipe segment 601 below the inspection port, and the diameter of the second air outlet pipe segment 602 is equal to the first air outlet pipe segment 601 below the inspection port.

[0042] In one embodiment, as shown in Figures 4-5, a second drainage pipe 12 is further provided in the vertical shaft 3. The lower portion of the second drainage pipe 12 is passed through the sealing plug 4 and the lower end extends into the water collection well 7. The upper end of the second drainage pipe 12 extends to the ground and is connected to a water pump. In this way, the groundwater discharged into the water collection well 7 can be pumped to the ground by the water pump.

[0043] In one embodiment,

[0044] As shown in FIG6 , the drainage blind pipe assembly includes a plurality of annular drainage blind pipes 13 and a plurality of longitudinal drainage blind pipes 14. The annular drainage blind pipes 13 are arranged annularly around the outer surface of the underground gas storage cavern segment 101. The axis of the longitudinal drainage blind pipe 14 coincides with the axis of the underground gas storage cavern segment 101 and is arranged at a corresponding position on the outer surface of the underground gas storage cavern segment 101. The longitudinal drainage blind pipe 14 at the bottom of the outer surface of the underground gas storage cavern segment 101 is called a bottom longitudinal drainage blind pipe 15. Each annular drainage blind pipe 13 is connected to each longitudinal drainage blind pipe 14. The bottom longitudinal drainage blind pipe 15 in the underground gas storage cavern segment 101 connected to the connecting tunnel 2 is connected to the second drainage ditch 10, and the diameter of the bottom longitudinal drainage blind pipe 15 is greater than 0. It is larger than the diameter of the remaining longitudinal drainage blind pipes 14; in this way, the groundwater at the underground gas storage cavern segment 101 can enter the bottom longitudinal drainage blind pipe 15 through the annular drainage blind pipe 13 and the remaining longitudinal drainage blind pipes 14 except the bottom longitudinal drainage blind pipe 15 in sequence, and the groundwater in the bottom longitudinal drainage blind pipe 15 in the underground gas storage cavern segment 101 that is not connected to the connecting tunnel 2 can enter the bottom longitudinal drainage blind pipe 15 in the underground gas storage cavern segment 101 connected to the connecting tunnel 2, and the groundwater in the bottom longitudinal drainage blind pipe 15 in the underground gas storage cavern segment 101 connected to the connecting tunnel 2 can enter the water collection well 7 through the second drainage ditch 10, so the groundwater at the underground gas storage cavern segment 101 can be quickly discharged to the water collection well 7.

[0045] The horizontal heights of the two ends of the bottom surface of the underground gas storage cavern segment 101 connected to the connecting tunnel 2 are higher than the horizontal height of the bottom surface at the position connected to the connecting tunnel 2, so that the groundwater in the bottom longitudinal drainage blind pipe 15 of the underground gas storage cavern segment 101 connected to the connecting tunnel 2 can easily enter the second drainage ditch 10 by gravity.

[0046] In one embodiment, as shown in FIG6 , the underground gas storage cavern segment 101 comprises, from the outside to the inside, a concrete spraying layer 1011 , a reinforced concrete lining layer 1012 and a sealing layer 1013 . The sealing layer 1013 is formed by welding a plurality of steel plates end to end in sequence.

[0047] In one embodiment, as shown in Figures 1, 2 and 4, a vehicle passing tunnel 16 connected to the connecting tunnel 2 is provided on both sides of the connecting tunnel 2 to facilitate the passage of vehicles and construction machinery in the connecting tunnel 2.

[0048] A construction method for a compressed air energy storage underground gas storage device comprises the following steps:

[0049] S1. First, excavate the vertical shaft 3. After the vertical shaft 3 is penetrated, excavate the connecting tunnel 2 in two working faces with the vertical shaft 3 as the center. When excavating the connecting tunnel 2, excavate a water collection well 7 at the outer bottom wall of the connecting tunnel 2, and arrange a second drainage ditch 10 at the outer bottom wall of the connecting tunnel 2. After the connecting tunnel 2 is penetrated, excavate an underground gas storage cavern segment 101 connected to the connecting tunnel 2 through the connecting tunnel 2. Then, excavate other underground gas storage cavern segments 101 through the excavated underground gas storage cavern segments 101. When excavating the underground gas storage cavern segments 101, arrange drainage blind pipe assemblies on the outer periphery of the underground gas storage cavern segments 101, and connect the drainage blind pipe assemblies to the second drainage ditch 10.

[0050] S2. After the excavation of all underground gas storage cavern segments 101 is completed, the concrete spraying layer 1011, the reinforced concrete lining layer 1012 and the sealing layer 1013 are constructed. Then, a sealing plug 4 is arranged at the intersection of the vertical shaft 3 and the connecting tunnel 2, and an air inlet pipe 5 and an air outlet pipe 6 are arranged in the vertical shaft 3. The lower ends of the air inlet pipe 5 and the air outlet pipe 6 are passed through the sealing plug 4 and connected to the connecting tunnel 2. Then, the first drainage ditch 8 around the top edge of the sealing plug 4 in the vertical shaft 3 is connected to the water collection well 7 through the first drainage pipe 9.

[0051] In summary, the compressed air energy storage underground gas storage device of the present invention is safe, has a large gas storage capacity, is applicable to a wide range of geological conditions, and has low cost.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A compressed air energy storage underground gas storage device, characterized in that: The invention comprises an underground gas storage cavern (1) located in an underground surrounding rock, wherein the underground gas storage cavern (1) is formed by splicing a plurality of underground gas storage cavern segments (101) end to end in sequence, wherein a connecting tunnel (2) is provided between two non-adjacent underground gas storage cavern segments (101), a vertical shaft (3) connected to the ground is provided at the top of the connecting tunnel (2), a sealing plug (4) is provided at the intersection of the vertical shaft (3) and the connecting tunnel (2), an air inlet pipe (5) and an air outlet pipe (6) are provided in the vertical shaft (3), and the air inlet pipe (5) and the air outlet pipe (6) are provided in the vertical shaft (3), and the air inlet pipe (5) and the air outlet pipe (6) are provided in the vertical shaft (3). The lower ends of the gas pipelines (6) pass through the sealing plugs (4) and are connected to the connecting tunnels (2); a water collecting well (7) is provided at the outer bottom wall of the connecting tunnel (2); a first drainage ditch (8) is provided around the top edge of the sealing plug (4) in the vertical shaft (3); the first drainage ditch (8) is connected to the water collecting well (7) through a first drainage pipe (9); a drainage blind pipe assembly is provided on the outer periphery of the underground gas storage cavern segment (101); the drainage blind pipe assembly is connected to the water collecting well (7) through a second drainage ditch (10) provided at the outer bottom wall of the connecting tunnel (2).

2. A compressed air energy storage underground gas storage device according to claim 1, characterized in that: The underground gas storage cavern segments (101) are cylindrical in shape, adjacent underground gas storage cavern segments (101) are integrally connected and the connection is in an arc shape, and the connecting tunnel (2) is integrally connected to the corresponding underground gas storage cavern segments (101).

3. A compressed air energy storage underground gas storage device according to claim 1, characterized in that: The air intake pipe (5) is a three-way pipe, comprising a first air intake pipe segment arranged vertically and two second air intake pipe segments arranged horizontally, the upper part of the first air intake pipe segment is located in the vertical shaft (3) and the lower part is located in the sealing plug (4) below the vertical shaft (3), one section of the second air intake pipe segment is located in the sealing plug (4) on one side below the vertical shaft (3), and the other section of the second air intake pipe segment is located in the sealing plug (4) on the other side below the vertical shaft (3), one end of the second air intake pipe segment is connected to the lower end of the first air intake pipe segment, and the other end passes through the sealing plug (4) and is connected to the connecting tunnel (2).

4. A compressed air energy storage underground gas storage device according to claim 3, characterized in that: The structure of the air outlet pipe (6) is the same as that of the air inlet pipe (5). The air outlet pipe (6) comprises a first air outlet pipe segment (601) arranged vertically and two second air outlet pipe segments (602) arranged horizontally. The air outlet pipe (6) is used as an inspection pipe. An inspection port is provided at the first air outlet pipe segment (601) near the top surface of the sealing plug (4), and a sealing blind plate (11) is provided at the inspection port.

5. A compressed air energy storage underground gas storage device according to claim 1, characterized in that: A second drainage pipe (12) is also provided in the vertical shaft (3), the lower end of the second drainage pipe (12) extending into the water collection well (7) and the upper end extending to the ground and connected to a water pump.

6. A compressed air energy storage underground gas storage device according to claim 5, characterized in that: The water collection well (7) is located at the outer bottom wall of the connecting tunnel (2) below the vertical shaft (3); the first drainage pipe (9) is inserted into the sealing plug (4) and the lower end extends into the water collection well (7); the second drainage ditch (10) is arranged along the extension direction of the connecting tunnel (2) and is arranged on the entire outer bottom wall of the connecting tunnel (2); the lower part of the second drainage pipe (12) is inserted into the sealing plug (4).

7. A compressed air energy storage underground gas storage device according to claim 1, characterized in that: The drainage blind pipe assembly comprises a plurality of annular drainage blind pipes (13) and a plurality of longitudinal drainage blind pipes (14). The annular drainage blind pipes (13) are arranged annularly around the outer surface of the underground gas storage cavern segment (101). The axis of the longitudinal drainage blind pipe (14) coincides with the axis of the underground gas storage cavern segment (101) and is arranged at a corresponding position on the outer surface of the underground gas storage cavern segment (101). The longitudinal drainage blind pipe (14) located at the bottom of the outer surface of the underground gas storage cavern segment (101) is called a bottom longitudinal drainage blind pipe (15). Each of the annular drainage blind pipes (13) is connected to each longitudinal drainage blind pipe (14), wherein the bottom longitudinal drainage blind pipe (15) in the underground gas storage cavern segment (101) connected to the connecting tunnel (2) is connected to the second drainage ditch (10).

8. A compressed air energy storage underground gas storage device according to claim 7, characterized in that: The horizontal heights of the two ends of the bottom surface of the underground gas storage cavern segment (101) connected to the connecting tunnel (2) are higher than the horizontal height of the bottom surface at the position connected to the connecting tunnel (2).

9. A compressed air energy storage underground gas storage device according to claim 1, characterized in that: The underground gas storage cavern segment (101) comprises, from outside to inside, a concrete spraying layer (1011), a reinforced concrete lining layer (1012) and a sealing layer (1013), wherein the sealing layer (1013) is formed by welding a plurality of steel plates end to end in sequence.

10. A construction method for a compressed air energy storage underground gas storage device according to any one of claims 1 to 9, characterized in that The following steps are involved: S1, excavating the vertical shaft (3) first, and after the vertical shaft (3) is connected, excavating the connecting tunnel (2) in two working faces with the vertical shaft (3) as the center, and when excavating the connecting tunnel (2), excavating a water collection well (7) at the outer bottom wall of the connecting tunnel (2), and arranging a second drainage ditch (10) at the outer bottom wall of the connecting tunnel (2), after the connecting tunnel (2) is connected, excavating an underground gas storage cavern segment (101) connected to the connecting tunnel (2) through the connecting tunnel (2), and then excavating other underground gas storage cavern segments (101) through the excavated underground gas storage cavern segments (101), and arranging a drainage blind pipe assembly on the outer periphery of the underground gas storage cavern segment (101) when excavating the underground gas storage cavern segment (101), and making the drainage blind pipe assembly connected to the second drainage ditch (10); S2. After all the underground gas storage cavern sections (101) are excavated, a sealing plug (4) is arranged at the intersection of the vertical shaft (3) and the connecting tunnel (2), and an air inlet pipe (5) and an air outlet pipe (6) are arranged in the vertical shaft (3), and the lower ends of the air inlet pipe (5) and the air outlet pipe (6) are passed through the sealing plug (4) and connected to the connecting tunnel (2), and then a first drainage ditch (8) around the top edge of the sealing plug (4) in the vertical shaft (3) is connected to the water collection well (7) through a first drainage pipe (9).